<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<button id="btn" onclick="goceshi()">回退</button><!--1.在75页点击下一页出现76页 2.在76页里有一个回退按钮 点击之后回到75页-->
<script>
    function goceshi() {
        history.back();
    }
</script>
</body>
</html>